The present invention relates to a structure of connection between an output shaft of an expander, particularly, a member in which an expansion energy of a raised pressure vapor serving as an operating medium is converted into a rotating energy for the output shaft, and a transmitting shaft of a driven member.
Such an expander is conventionally used, for example, as a motor in a Rankin cycle. There is such a conventionally known connection structure in which an end of an output shaft is located to protrude to the outside from a casing of an expander and is connected to the transmitting shaft through a gear device (for example, see Japanese Utility Model Publication No.1-33768).
Of course, a seal member is mounted in an output shaft-insertion bore provided in the casing, but the following problem is encountered: The raised-pressure vapor may be leaked to the outside through between the seal member and the output shaft, and such leakage of the vapor to the outside results in a reduction in amount of the operating medium, thereby detracting the function of the Rankin cycle and failing the maintaining of the performance.
It is an object of the present invention to provide a connection structure of the above-described type, wherein the output shaft of the expander and the transmitting shaft of the driven member can be connected to each other to prevent the leakage of the raised-pressure vapor serving as the operating medium to the outside.
To achieve the above object, according to the present invention, there is provided a structure of connection between an output shaft of an expander and a transmitting shaft of a driven member, comprising a cover member mounted on an outer surface of a casing of an expander in which an energy of expansion of vapor having a raised pressure is converted into a rotating energy for an output shaft, the cover member having a function of sealing an end of the output shaft protruding on the outer surface of the casing against the outside and a function of recovering vapor discharged from the casing and having a dropped pressure after the conversion, and a connecting member for connecting the end of the output shaft located within the cover member and the transmitting shaft of the driven member disposed outside the cover member, so that a power can be transmitted.
With the above arrangement, the output shaft and the transmitting shaft of the driven member can be connected to each other with the periphery of the end of the output shaft being sealed, so that the power can be transmitted. In addition, the raised-pressure vapor leaked from the sealed portion of the output shaft in the casing is recovered by the cover member and hence, cannot be leaked to the outside. Further, the recovered vapor is dropped in pressure within the cover member and fed to the condenser, for example, along with the dropped-pressure vapor discharged from the casing. Thus, it is possible to avoid a reduction in amount of the operating medium to maintain the function of the Rankin cycle and the performance.